Hartzell Inc. had the following data for $2020,$ in millions: Net income $=$ $$600$; after$-$tax operating income $[$EBIT$(1-$ T$)]=$ $$700$; and Total assets $=$ $$1,700.$ Information for $2021$ is as follows:

Net income $=$ $$825$; after$-$tax operating income $[EBIT(1-T)]=$$$1,700$; and Total assets $=$$$2,250.$ Assume the firm had no excess cash. How much free cash flow did the firm generate during

$2021?$

a$.$ $$275$ million

b$.$ $$2,250$ million

c$.$ $$1,375$ million

d$.$ $$1,150$ million

e$.$ $$1,475$ million